Stump grinder stumped

[Gareth J]

What's the next size down taperlock? If only a mm or two, do your weld repair, true up and turn down undersize.

The shaft was oversized enough to munch the keyway instead of snapping, droping a couple mm will probably be more achievable considering the shaft already looks trashed and you'll probably end up warping it a bit anyway.

 

[Screwdriver]

it isnt i dont feel
so screwdriver is aware the taper is a how to pulley locks, the pulley has a taper which a bush with outside matching taper is pulled into tightening the bush

Actually I didn't know how this fixing worked (I'm not even sure if it does!) but it certainly looks like it has a taper on the shaft now! That is some crazy wear if that's the case. I will get off my **** and go have a look (any minute now).

(I'm also trying to jury rig a remote monitor for my camera to avoid any more embarrassing out of focus/out of shot or badly composed videos).

 

[mtt.tr]

Actually I didn't know how this fixing worked (I'm not even sure if it does!) but it certainly looks like it has a taper on the shaft now! That is some crazy wear if that's the case. I will get off my **** and go have a look (any minute now).

(I'm also trying to jury rig a remote monitor for my camera to avoid any more embarrassing out of focus/out of shot or badly composed videos).

they come loose once that happens and its missed we end up where you are now

 

[Kram]

Does this part need to be removable once its fitted? After its turned round, you could make up a larger shrink fit sleeve, cut a crude keyway in the sleeve and use the biggest taperlock to fit the pulley.

 

[mtt.tr]

Does this part need to be removable once its fitted? After its turned round, you could make up a larger shrink fit sleeve, cut a crude keyway in the sleeve and use the biggest taperlock to fit the pulley.

yes as they sit on a set of plummer blocks

 

[Kram]

Does it need to be often stripped for maintence, or once assembled can it be semi permenent?

 

[mtt.tr]

Does it need to be often stripped for maintence, or once assembled can it be semi permenent?

the bearings are almost disposable they sit right in the dirt often full of soil after a few jobs

 

[bricol]

Taperloc is a little misleading... shaft needs to be parallel

Not really - its, tapered, and it locks. Well known, quite old, device. Quite a few people make them - I've used them for 30 yrs for low cost connections to shafts that don't need to take much torque.
If you look here, it should be clear:

https://www.fptgroup.com/dss/docs/689_06_Fenner_Shaft_Fixings.pdf

Scroll down and you will see their "Fenlocks" which are really Tollok locking bushes - they transmit more torque than a simple taper lock, although work on the same idea. Ringfeder are the ones you want if you want full technical back up - I needed a locking device for a 100mm dia shaft that not only needed to transmit high torque, but also a considerable bending moment - one supplier said "huh?" in best Homer accent as the question was quite a long way above his pay grade . . . another said "we don't know", which is fair enough . . . Ringfeder told me what I needed to know - my only problem then was ensuring our purchasing dept actually bought what I specified rather than what they could get for a cheaper price that their chosen supplier said was the same - I've been caught out by their clever decision making before!

A proper tapered fit onto a shaft, if you do it properly, is expensive and difficult to get right if you want the components to fit concentrically to a tiny tolerance, and be in the right place along the shaft when it stops. As many of our suppliers are proving at the moment with one of the machines we supply, much to one of my colleagues consternation! No helped by our inspection dept not being able to agree with theirs on what is actually incorrect.

 

[My Old Landy]

I can't help with any suggestions, but I enjoyed the video and subscribed

 

[Screwdriver]

Once again I am rendering out a video. 7 minutes long, should be done by tea time

Anyway, the long and the short of it is, it is bent, at least 0.7mm or 27 thou in old money. That's too much even for me plus it does have a slight taper (possibly a compound bend) but irrelevant. I need to speak to the owner. It's too badly mullered to mess about with it.

I wish I had taken the whole machine then it would have been easier to figure out some of the stuff I am just discovering, like the possibility of swapping the shaft around. Sounds good to me! Anything but cut and weld a new shaft. I'd do it to my own equipment but I wouldn't do a drastic repair like that to someone else's. Not on a machine like this!

Just out of interest, I have left a message for Viktor and I might suggest he needs a professional repair (new shaft). Would anyone here like to take that on as a job? What would that cost? PM if you prefer. I think he's more interested in turnaround time and I'm definitely not welding a new shaft onto a stump grinder so I'm not fishing for a quote. Doing a repair like that is beyond my pay grade.

He's just around the corner so might pop in and I can show him. I still think he'll want me to just weld up the damage and bung a key on but at least I can explain the issues and he can be responsible for the carnage. He's been a tree surgeon for so many years he's half deaf and it's difficult enough talking face to face (he really shouts!). There's also a slight language barrier so I'm hoping I can just show him and explain the problems...

 

[Screwdriver]

I can't help with any suggestions, but I enjoyed the video and subscribed

Thanks. The next 7 minutes are almost half done. I may need to develop my workflow or get a faster machine (or both).

 

[mike os]

Probably as cheap to buy the shaft and plate as a unit by the time you have made a decent repair..... I would want a whole new shaft passing through the plate....

 

[Screwdriver]

Probably as cheap to buy the shaft and plate as a unit by the time you have made a decent repair..... I would want a whole new shaft passing through the plate....

Plate is 500 quid on its own iirc.

 

[Kram]

Anyway, the long and the short of it is, it is bent, at least 0.7mm or 27 thou in old money. That's too much even for me plus it does have a slight taper (possibly a compound bend) but irrelevant. I need to speak to the owner. It's too badly mullered to mess about with it.

How did you clock it in? You need two references. The face of the plate doesnt look too good so I'd be using both ends.
I wouldnt say 0.7mm out is a problem for this machine. Im assuming this has a lot of torque but spins slow?

 

[James1979]

How did you clock it in? You need two references. The face of the plate doesnt look too good so I'd be using both ends.
I wouldnt say 0.7mm out is a problem for this machine. Im assuming this has a lot of torque but spins slow?

They spin really fast. It’s like a demented beaver

 

[MattF]

Plate is 500 quid on its own iirc.

Which is likely why he's wanting it doing cheap, & will bug you over any future problems with the machine, forever. Say no, & hand it back.

 

[Screwdriver]

How did you clock it in? You need two references. The face of the plate doesnt look too good so I'd be using both ends.
I wouldnt say 0.7mm out is a problem for this machine. Im assuming this has a lot of torque but spins slow?

I would need the owners advice regarding acceptable runout but my main concern is if I weld the keyway to repair it, it will warp even more. It is only a pulley so you're probably right. It was wobbling like a spinning plate on a stick and I am pretty sure he was still using it!

Once I saw how bad it was, I didn't bother dialling it in perfectly wrt the plate for example. Video is probably done by now, let me go take a peek...

 

[Screwdriver]

Yes it is.

..and I'm not even the first viewer! I set Premiere to auto upload and it did too,

 

[Screwdriver]

Don't increase it - but if you have to give it a clean up to get a good surface/true it up and remove material, the current bush won't work properly - and for the sake of a few quid, get the right size bush - specced by the bush number (1610) and the required bore (your original is 25 bore) - so if you needed to drop it to 24 dia - 1610-24.

I think this is the golden nugget I was looking for and it does solve the issues I recently discover. I think that type of repair is on the edge of acceptability for me.

1. I can probably make a decent job of repairing the keyway
2. I can turn down the shaft
3. That will also clean up any runout and excess weld+distortion
4. Those taperlock jobbies are about a fiver

Only issue is time. Time to order up and receive the correct part (and swap it for an actually "correct" part). Otherwise I think that is certainly the most cost effective option.

Many thanks!

 

[Screwdriver]

Pulley looks ok and in any case, there's a new insert for it as shown in exhibit #A.